Here is the full list of all 40 METALLIC CHILD achievements.
Defeat the Metallic Child, Lighton.
Defeat the Metallic Child, Spyden.
Defeat the Metallic Child, Flyer.
Defeat the Metallic Child, Shutty.
Perform 200 Take-downs.
Help retrieve Sly's weapons 20 times.
Accomplish 30 combos.
Defeat 3000 enemies.
Install 200 bugged and viral Cores.
Install 150 Super-cores.
Defeat the Metallic Child, Icela.
Defeat 20 of Catherine's modified robots.
Rescue 20 survivors.
Deal 600 damage or more to an enemy in a single hit.
Defeat the Metallic Child, Faceless.
Defeat the Metallic Child, Controd.
Be graded an S for battle 100 times.
Accomplish = double kills.
Install 150 Mini-cores.
Defeat the Metallic Child, Gigantic.
Defeat the Metallic Child, Graver.
Defeat the Metallic Child, Fira.
Experience a defeat in battle.
Visit the various facilities of Life Stream.
Defeat all Metallic Childs.
Defeat the Metallic Child, Magna.
Clear all Virtual Missions.
Clear Terminal Creed.
Accomplish 100 triple kills.
Accomplish 30 fantastic kills.
Perform 200 Chain-skill attacks.
Go on camera 20 times, for Miamo's live stream.
Open Daviny's box 20 times.
Help deliver Trevon's virus case 20 times.
Repair Schrodinger 20 times.
Be graded a D for battle 100 times.
Collect all Recor-Ds.
Collect all Fan-art.
Change weapons 100 times during battle.
Equip a drone 100 times during battle.